If the ice sheets on Greenland ever melt, this is what you'll see. It's an enormous canyon cutting through the center of the island, the size of the Grand Canyon. Scientists recently discovered it with ice-penetrating radar.

The canyon is up to 2,600 feet (800 meters) deep, and its scale in width and length rivals parts of the Grand Canyon in Arizona. It starts beneath the ice in central Greenland and winds its way north to drain into the Arctic Ocean, according to new research from scientists at the University of Bristol, as well as researchers from Canada and Italy. The finding helps explain why Greenland doesn’t have pools of water under its ice sheet like Antarctica does: The canyon may be helping divert meltwater and thus keeping Greenland’s ice sheet stable.

Millions of years ago, when Greenland wasn't crushed under its massive ice sheet, this canyon might have been a lush region full of rivers, plants and animals. But then climate fluctuations lowered temperatures, destroying all life in this once-fecund area.